Body implantable stimulators are known to the prior art, the most common being the cardiac or heart pacemaker. Typically, such stimulators are formed of a separable electrical lead and a signal generator with provision being made to electrically and mechanically connect the lead and generator to complete the stimulator unit.
Many prior art signal generators have been found following assembly by casting the components, including mechanical and electrical connections for the lead, in a matrix of encapsulating material which supports the components and shields them from the body environment. Typically, the encapsulating material is an epoxy.
In the body environment, it is generally recognized that an enclosed and hermetically sealed signal generator is more reliable as a result of the known and controlled environment provided by the hermetic seal. For this reason, many recent signal generator designs include a rigid enclosure formed of a plurality of preformed members which are typically welded together to complete the enclosure. The connection between the generator and the electrical lead, when it is desired that these members be separable, occurs outside of such an enclosure. It is common to cast an interconnect assembly from epoxy. However, it would be beneficial to eliminate the epoxy encapsulation process. Thus, a preformed connector assembly, which may be reliably secured to a preformed enclosure housing the generator components, would greatly facilitate assembly of the stimulator. The amount of handling would be reduced with the remaining handling being easier to perform than an epoxy casting process. One type of preformed connector assembly is disclosed in application Ser. No. 793,642, filed May 4, 1977, in the name of Richard A. Jones and now issued as U.S. Pat. No. 4,154,248, which application is commonly owned with the present application.
The above referenced application provides a preformed connector assembly thereby eliminating the necessity of forming that assembly in place, as by an epoxy casting process, for example. In that assembly, the electrical connection between the connector assembly terminal and the signal generator requires manipulation of a wire to position it and a weld, or other similar process, to secure it in position. Thus, while the connector assembly of the above referenced application greatly reduces the handling necessary to form and complete a connector assembly on a signal generator unit, considerable handling remains necessary.